This invention relates to a small and portable data terminal apparatus for reading bar codes printed on paper or the like, reading, storing and displaying image data such as hand-written characters, and communicating with external equipment.
An apparatus combining a CCD scanner for reading bar codes and a small data terminal unit has been published. An example of its composition is shown in FIG. 1.
In FIG. 1, a surface of an object 1, on which the bar code is printed, is illuminated by a light source 2, and an image (bar code) of the object 1 is reflected by a mirror 3. The image is focused by a lens 4 on a CCD image sensor 5, which converts the incident light into an electric charge, transfers the signal charge by a CCD analog shift register, and outputs the stored charge in a serial manner. A waveform shaping circuit 6 shapes the output signal from the CCD image sensor 5 into a digital signal at specified timing. The digitized image data from the waveform shaping circuit 6 is passed through a control circuit 7 and stored in a memory circuit 8. A timing pulse generating circuit 9 is activated by the control circuit 7 and generates various kinds of timing pulses to operate the CCD image sensor 5. A CCD drive circuit 10 converts the timing pulses to specified voltage levels to operate the CCD image sensor 5. The image data (bar code pattern) stored in the memory circuit 8 is analyzed and converted into code data by the control circuit 7. Adisplay unit 11 shows the result of information processing by the control section 7. An input circuit 12 issues commands requesting various operations of the apparatus, and the commands are input into the control circuit 7. The above-mentioned code data and various items of information are passed through the control circuit 7, and output via a communication circuit 13 to external equipment.
As has been described, even conventional small data terminal equipment with a CCD scanner can read a unidimensional image (bar code), and digitize, store, analyze, display and output signals to external equipment.
A second example of the prior art is an image reader, the composition of which is shown in FIG. 2.
In FIG. 2, the surface of an object 21 is illuminated by a light source 22, and an image coming from the object 21 is reflected by a mirror 23. The image is focused by a lens 24 on a CCD image sensor 25, which converts the focused image into an electric charge and transfers the signal charge by a CCD analog shift register. The output from the CCD image sensor 25 is shaped into a specified waveform by a waveform shaping circuit 26 and becomes digital information. The digitized image data is output to external equipment 27. A timing pulse generating circuit 28 is activated by the external equipment 27 and generates various kinds of timing pulses. A CCD drive circuit 29 converts the timing pulses to specified voltage levels, which are used to drive the CCD image sensor 25. A roller 30 rotates when the apparatus is moved (made to slide). A timing detector 31 generates timing pulses as the roller 30 rotates. An amplifier 32 amplifies the timing pulses, and outputs the timing pulses to the external equipment 27. The external equipment 27 reads digitized unidirectional image data concerning the object 21, and stores and controls this data.
As described, while the apparatus is moved, the image reader of the second prior art example can read two-dimensional image data from the object, and digitize and output the data to the external equipment.
However, the above-mentioned prior-art small data terminal apparatus with a CCD scanner (FIG. 1) has the disadvantage that it cannot handle anything other than unidirectional images (bar code patterns). The prior art image reader (FIG. 2) can obtain two-dimensional image data by moving the apparatus, but has the disadvantage that the apparatus is not easy to handle because it is moved. Another disadvantage of this image reader is that the storage and display parts are included in the external equipment, and are not easy to handle.